Apparatus for and system of motor control



July 15 1924. 1501,661-

J. A. HEPPERLEN APPARATUS FOR AND SYSTEM OF MOTOR CONTROL Filed Feb. 19.1923 Shawl; Slowdown Lower.

I 4) a Raise-$J K Q 2 by% w H/ZS AttorneQ/ Patented July 15, 1924.

UNITED STAT eArENT OFFICE.

JOHN A. HErPEnLEn, or EAs'r ORANGE, NEW JERSEY, AssIGNon To GENERAL.Erec- TRIG COMPANY, A CORPORATION or NEW YORK.

APPARATUS FOR Ann SYSTEM 01? Moron con'rncn.

Application filed February 19. 1923. Serial No. 619,836.

To a ZZ whom it may concern: I

Be it known that I, Jenn A. HErrEnLEN, citizen of the United States,residing at East Orange, in the county of Essex, State of New Jersey,have invented certain new and useful Improvements in Apparatus for andSystems of Motor Control, of which the following is a specification.

This invention relates to apparatus for and a system of motor controlwhereby an electric motor may be started and stopped and generallycontrolled in a safe, reliable, simple and effective manner.

One of the objects of the invent-ion is to provide a control for anelectric motor whereby the speed of the motor may be varied through acomparatively wide range by the manipulation of comparatively few pushbuttons or other manually operable master switch mechanism.

Another object of the invention is to provide a control for an electricmotor where'- by the wide range of speeds is obtained without thenecessity of apower operated rem'ot ely controlled master switch, suchfor example, as a manually controlled pilot motor operated or controlledspeed varying controller as used in a full automatic type of control.

Another object of the invention is to prov'id'e an improved arrangementwhereby a predetermined maximum speed of the motor ls obtitlfl'ed at arate of acceleration which is controlled by means responsive to anoperating condition of the motor or the motor circuits, as for example,cont-rolling the rate of acceleration of the electric motor inaccordance with the current taken by the motor.

A further object of the invention is to provide an improved system ofmotor control in which a start push button, or other manually operablemaster switch for controlling the starting of the motor, may also beused as a slow down button, so that this single switch serves the doublepurpose of controlling the starting of the motor and of decreasing themotor speed after the motor has started.

A further object of the invention is to provide an arrangement involvingthe use of push buttons which may be biased to one position andautomatically returned there-to when the pressure on the push button isreleased, thus making itunnecessary to reset the button or buttonsbefore being trio motor, and eliminating the necessity for the use ofshutters on the push buttons for maintaining the push buttons in theiroperated positions.

Although my invention is not necessarily limited thereto it has aparticular application in the control of the electric driving motor ofmotors for a color printing press; Ordinarily, the practicaloondit'ionsimposed do not require the operation of these presses at anymore than either of two definite speeds. Thus, ordinarily, it iss'ulficient that a slow or threading speed be provided for and the fullrunning speed. In accordance with my invention, a full automatic ofcontroller for controlling the motor or motors of color printing pressesis dispensed with, and the very much simpler arrangement of my inventionserves the purpose equally well and nevertheless has a number ofadvantages from the standpoint of sim plicity of construction andarrangement, and therefore a greater reliability of operation. These andother objects of the invention, as will be either apparent to thoseskilled in the art or as will be pointed out fully hereinafter, areattained in the apparatus for and the system of motor control which isillustrated in the very simple diagram of the accompanying drawing whichhas been provided for explaining the principles of the invention.

Referring to the drawing, the electric motor 10 is adapted to drive aload such, for example, as a color printing pres, and this motor iscontrolled by apparatus and in a manner hereinafter set forth. Thismotor is indicated as of the type having a shunttiel'd 11 and a seriesfield 12, although in certain of the aspects of the invention theparticular type of the motor used is not of the essence of theinvention. This motor is arranged to be connected to the source ofsupply 13' by the line contactor 1 1, which is arranged in such a waythat when open it establishes a dynamic braking circuit for the motorthrough acircuit including the resistor 15, and when energized to closeto establish a circuit for the motor including the coil of the currentlimit acceleration relay 16, the coil of the overload relay 17, themotor armature, the commutatin'g field 18, se-iesyfield 12, the resistor19, and the resistor 29. The motor may be controlled by the manuallyoperable master switch mechanism which i indicated as a plurality arelocated at a convenient point about the press or other driven machine.As many of these push button stations as desirable may be located aboutthe driven machine, and I have merely indicated two such stations, but Iwould have it understood that my invention is not necessarily limited toany particular number of the push button stations. The start relay 21 isprovided for cooperating with the start push button for controlling thestarting of the press for normal running or for running at a reducedspeed. The normally closed electromagnetic switch 22 is provided forcontrolling a portion of the starting resistor 19 so as to short circuiteithera portion or all of this resistor at starting'so as to obtain ahigh starting torque for the motor and then to automatically open whenthe motor speed has increased to the proper value so as to automaticallyreinsert the portion of the starting resistor 19 which is determined bythe adjustable switch 23, and thus obtain a predetermined operatingspeed. The high torque contactor 22 is connected so as to be energizedresponsively to the counterelectromotive force of the motor so as tothereby control the operation of this switch in accordance with thespeed of the motor.

Contactor 2 is provided for short circuting the entire starting resistor19 and this contac'tor under the control of the speed up push buttons aswell as the start push button, will be hereinafter BX- plained. Thecontactor is preferably of the well known series contactor type which isarranged'to be magnetically held open when the current through theoperating magnet winding is comparatively high and to magnetically closeand be held closed magnetically when the current through the operatingwinding has dropped to a predeterminedvalue. The series contactor 25 isarranged to short circuit the starting resistors-19 and-.20 so as tothereby connect the motor directly to the supply circuit. It will beunderstood that the resistors 19 ;and.20 will ordinarily in practice bea single resistorwith taps so that the contactors 22, 2 1 and may shortcircuit the resistor in sections.

i control of the electromagnetic relay 2. wif

The rheostat which is included i.

t shunt field circuit of the motor s under the 7 11c is energized toshort circuit the shunt field rheostat 26 until the motor has beenconnected directly to the supply circuit by the closing of the seriescontactor 25. The arrangement is such that when the contactor closes,the winding of the relay 2. is sort circuited so that this relay willopen. hereby inserting the portion of the resistance of the rheostat 26in the shunt field circuit of the motor, as determined by the positionof the ratchet operated rheostat arm 28. This rheostat arm is adapted tobe ratcheted back and forth by the electro magnetic operating meansindicated so as to thereby vary the resistance in the shunt fieldcircuit of the motor and thus vary the normal full running speed ofv themotor. The electromagnetic ratcheting mechanism is under the control ofthe push buttons which are indicated lower and raise. The arrangement issuch that when the lower push button is pressed, the electromagneticratcheting mechanism is operated to decrease the value of the resistanceof the rheostat 26. and when the raise push button is depressed. toincrease the value of the resistance of the rheostat which is includedin the motor field circuit so as to thereby control the speed of themotor.

As thus constructed and arranged. and with the parts in their respectivepositions shown in the drawing, the operation of my invention is asfollows: Assume that it is desired to jog the press, that is, start thepress and operate at a comparatively low speed, the jog push button willbe depressed thereby energizing the winding of the line contactor 14through a circuit which may be traced from the upper supply conductoncontacts of the overload relay 1?, stop push buttons, through thecontacts of the particular j0g push button which has been pressed. thewinding of the line contactor, to the lower supply conductor. The motorarmature will be connected to the source of supply by't-he closing ofthe line contactor 14, and the resistor comprising the sections 19 and20 will be includedin the motor armature circuit. The high torquecontactor 22 will short circuit the predetermined portion of theresistor section 19 so as to obtain a high torque for the motor atstarting. As soon as the motor speed has increased, this contactor willautomatically thereby reinserting all of the resistor section 19 in themotor armature circuit. The motor will be disconnected from the sourceof supply and included in a dynamic braking circuit which includes thebraking resistor 15 when the jog push button is released. This providesfor operating the motor atva reduced speed for the prelimopen,

the speed asamm iiiaify operations making up' the press. The high torquematador 22 p'rsviaes for effecting a high motor torque at starting inorder to" perii'iit the load driven by the in the normal manner or tostart the motor so as to operate continuously ata reduced speed, thestart push buttonis momentarily r lepressed -so that the Contactmechanism of this push button Will' make en agement with its lower setof contacts. 'Ihis will effect the energization of the s t-art relay 21,which in closing completes the circuit for the Winding" of the line contactor 14 and also establishesa maintaining circuit for the relayWinding. so that the start push button may be released: to return intoengageinent with its upper set of contacts. The motor will now operateinthe manner previously explained in connection" with the olperat-ion ofthe jog buttombut in this case t (2 motor will continue to run after thestart button has been released: If it is desired to increase the speedofthe motor,

up button is momentarily depressed; thereby energizing. the resistorc611- ta'ctor 24 to close and short circuit the resisto'r' section- 19'.hen the. resistor contactor 24 closes; it opens the Windingcirc'uif'of'the high torque contactor 22 at the lower auxiliarycontactsand closes acircuit throughthe upper auxiliary contacts, sothat thewinding of the contactor is maintained energized through a circuitWhich-Cincludes the upper contacts of the start push button: It willalso be observed that the closing of the resistor contactor 24has-energized the series operating coil of the current limitaccelerating contactor 25.

This, contactor will be magnetically held open when the motor currentishigh, -and when the motor current is reduced to the predetermined value,the contactor will be magnetically closed so as to short circuit theentire starting resistor and-connect the motor armature directly/to thesupply circuit' for full speed operation. When the contactor'25 closes,it short circuits the series operating coil thereof; but the contactoris maintained closed by reason of the fact that the shunt coil of thiscontactor is energized when the switchis closed so as'to magneticallyhold the switch in the closed position;

Assume that it'is'now desired to decrease the motor speed; This may bedone by momentarilydepressing thestart push button so as to' therebydeenergize the resistor contactor 24. The resistor c'ontactor 24 willthus open'andthe" shu'nfi holding winding In order to startthemotor fordperatisn.

or the, contactdr' 25 will be deene'rgized by reason of the fact" thatthe shunt of this" c'ont'actor was maintained energized through theupper auxiliary cohtaets of the resistor contactor 24. The high torquecontactor 22 will be energized to openrby reason of the fact that themotor speed isabove the predetermined value" so t at the resistorsections 19 and 20 are ineluded in the nfotorlarmature circuit. Themotor is this caused to operate at the predetermined reduced speed. Inorder to stop the motor'after the motor has" been started by any ofthemeans provided, the spring return stoppush button is momentarily de--pressed, thereby deenergizing the line conta'ctor 14.; disconnectingthemotor from the source of supply, and connecting the motor armature in adynamic brake circuit.

It will be observed that the shunt field rheostat 26 is automaticallyshort circuitedwhen the motor is first connected to the supply circuitby reason of the fact that the field relay 27 will simultaneously closewith the closing of the line contactor 1 1. As soon as" the seriescontactor 25 closes, however, the Winding of the relay 27 is shortcircuited so that this relay Will openand insert the portion of theresistance of the rheostat 26 in the motor field circuit as determinedby the setting of the" rheostat arm 28. The current limit relay 16 Willautomatically effect the acceleration of the motor to the full runningposition in accordance with the current taken by the motor by reason ofthe fact. that this relay Will alternately short circuit shunt fieldrheo'sta't 26 and open the shunt until the motor has accelerated to thefull running speed and the current takenby the motor has dropped to thenormal full load current of the motor. If it is desired that the motorspeed shall be increased, the push button: marked raisev isdepressed,thereby energizing" the" associated elect-romagnet of theelectromagnetically controlled ratchet arrangement so as toi-ncrezisethe value of the resistance of the rheost at 26 which is included theshunt field circuit of the motori In order to decrease the motor speedby shunt field control. the push; button marked lower isdepressed' so asto co'ntrol the electromagneticallyoperated ratcheting arrangement so asto cut out the resistance in the mbtor field circuit. Inasmuch as myinvention is not limited to any. particular type of controller forvarying the speed of the motor by shunt field control; it is he.- lieredthat those skilled in the art will readily understand this feature ofthe arrange mcnt shown in the drawing, particularly because of the factthat the shunt field ratcheting controller is adiagrammatic'representation of a type of controller well understoodbythose skilled in the art.

From the foregoing it willwbe seen that my invention provides a verysimple and effective arrangement for startin a 1d varying the speed ofan electric motor by means of a comparatively few controlling devices.The startpush button may also be used as a slow down button, and springreturned push buttons may be used throughout if desired. The advantageof a spring returned push button is that it is not necessary to resetthe button before being able to operate, as in the case where a snapswitch is used. Another advantage is that in starting the equipment theoperator is not required to hold down the speed upor fast push buttonuntil the motor has accelerated to the desired speed. v since in myarrangement by merely pressing the speed up push button momentarily themotor is automatically accelerated to the predetermined tull runningspeed and the acceleration of the motor is efl'ected in a safe, simple,and reliable manner. Another advantage of my arrangement is that thepush button control wiring is so simple in arrangement that any desirednumber of push button stations may be provided for the control of theelectric motorwithout introducing complications to provide againstimproper operation of the push buttons. In the drawinglhave merelyindicated two push button stations, but it will be obvious to thoseskilled in the art that the number of push button stations may be anynumber desired. i

In accordance with the provisions of the patent statutes, I havedescribed the principle of operation of my invention, together with theapparatus which I now consider to represent the best embodiment thereof,but I desire to have it understood that the apparatus shown is onlyillustrative and that the invention can be carried out by other means,

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is

1. The combination in a system of motor control of, a line contactor,electroresponsive switch mechanism for controlling the motor speed, twoindependently operable spring return push buttons for controlling thesaid line and speed controlling switch -mechanism, and connectionswhereby the said line contacto-r is energized to close and remain closedto cause the motor to run at a reduced speed by momentarily depressingone of said push buttons and then releasing the same, the said speedcontrolling-switch mechanism is energized to increase the motor speed bymomentarily depressing and then releasing the second of said pushbuttons, and the speed of the motor is reduced by momentarily depressingthe first of said push buttons.

2. The combination in a system of motor control of electroresponsiveline switch mechanism, electroresponsive means for controlling the motorspeed, a starting switch and a speed up switch, and connections wherebythe line switch mechanism is energized to close when the starting switchis temporarily operated and is maintained closed when the startingswitch is returned to'its original position, and the saidelectroresponsive means is energized to effect an increase of the motorspeed when the speed up switch is closed and then maintained energizedthrough a circuit controlledgby the starting switch when the speed upswitch is opened.

- 3. The combination in a system of motor control of electroresponsiveline switch mechanism, a manually operable starting switch biased to oneposition and operable to a second position to energize the said lineswitch mechanism to close and to be maintained closed when the startingswitch is returned to its biased position, electroresponsive speedcontrol switch mechanism and resistance in the motor circuit controlledthereby, a manually operable speed up switch biased to the open positionfor controlling the said switch mechanism, and'connections whereby thesaid speed control switch mechanism is -operated to short circuit aportion of the said resistance when the said speed up switch istemporarily closed and to then short circuit the entire resistance underthe control of the motor current, and the said speed control switchmechanism is opened to reinsert a portion of the said resistance in themotor circuit when the said starting switch is moved from its biasedposition.

4. The combination in a system of motor control of a line contactor, aresistor for controlling the'motor speed, a plurality of contactors forcontrolling the said resistor to vary the motor speed, two spring returnpush buttons for controlling the said line and resistor cont-actors, andconnections whereby the motor is started to run at a predeterminedreduced speed by momentarily depressing one of the said push buttons andthen releasing the same, the speed of the motor increased andaccelerated to full running speed in accordance with the motorcurrent bymomentarily depressing and then releasing the second of said pushbuttons, and the speed of'the motor reduced to the said predeterminedspeed'by momentarily depressingand then releasing the first of said pushbuttons. 5. The combination in a system of motor control of aresistor'having a plurality of sections for controlling the motor speed,a normally closed high torque contactor for short'circuiting apredetermined portion of one of the sections of'said resistor andconnected to open when the motor has attained a predetermined speed, aspeed up contactor for short circuiting the entire section of theresistor controlled by the said high torque contactor, a contactorenergized responsively to the closing of said speed up contactor andcontrolled responsively to the motor current for short circuiting thesaid resistor, a plurality of push buttons for controlling the saidcontactors, the said push buttons being biased to predeterminedrespective positions, and connections whereby the motor is started, thespeed thereof is increased or decreased or the motor is stopped byselectively temporarily depressing the said push buttons against theirbias.

6. The combination in a system of motor control of a line contactor, aresistor for con trolling the motor speed, a plurality of contactors forcontrolllng the same resistor to vary the motor speed, at least one ofsaid resistor contactors connected to automatically operate inaccordance with a motor operating condition, a spring return startbutton, a

spring return speed up button, a spring return stop button, andconnections whereby momentarily depressing the said start buttonconnects the motor to a source of supply to run at a predeterminedreduced speed,

momentarily depressing the said speed up button energizes the resistorcontactors to automatically accelerate the motor to full running speed,momentarily depressing the said start button deenergizes the saidresistor contactors to decrease the speed of the motor to the saidpredetermined reduced speed, and momentarily depressing the said stopbutton disconnects the motor from the source of supply.

In Witness whereof, I have hereunto set my hand this fifteenth day ofFebruary, 1923.

JOHN A. HEPPERLEN.

